I don't have the exact date of when Jubei was added to Central Fiction off the top of my head. But a good way to find out is to look at the game's patch notes or ask other dedicated players in online gaming communities.
One common theme is friendship. Since Naruto is known for his ability to befriend others, in fanfiction with Kagero, they often form a strong bond of friendship. Another theme is growth. Both characters usually grow as ninjas and as individuals through their interactions.
The unique combination of Naruto's well - known character and Kagero's less - explored character makes it unique. It allows for new storylines that deviate from the main Naruto plot.
Growth is also a major theme. Both Naruto and Kagero can experience personal growth in these fanfics. For example, Naruto might learn new jutsu from Kagero or gain a new perspective on life, and Kagero could become more open - hearted through her interactions with Naruto.
Well, Jubei in BlazBlue Central Fiction has distinct features. One of them is his agility. He can move around the battlefield very quickly, which gives him an edge in combat. Also, his special attacks often have a wide range of coverage, allowing him to control the fight to some extent. His design is also quite appealing, with his traditional Japanese look.
Perhaps an old rival of Jubei's who has turned to the dark side. This character would know all of Jubei's weaknesses and fighting styles, making them a formidable foe. They could be plotting to take over the BlazBlue world and see Jubei as the biggest obstacle in their path.
I have no clear knowledge of when Jubei will be released in Central Fiction. Maybe you can search in gaming forums or follow the game's social media accounts to get the latest on this.
Maybe a fanfic where Jubei takes on a young apprentice. This could show his mentoring side and how he imparts his knowledge and skills. You could include scenes of training, as well as the apprentice getting into trouble and Jubei having to rescue them, all while teaching important life lessons.